Accurate, non-invasive determination of multiphase fluids distribution in reservoir rock can greatly help the evaluation and monitoring of oil reservoirs. This laboratory thesis research, carried but utilizing the biomedical engineering concepts and measurement facilities, is an important step in developing a novel magnetic field-based oil detection method. When paramagnetic nanoparticles are either adsorbed oil/water interface or dispersed in a fluid phase in reservoir rock pores, and exposed to external magnetic field, the resultant particle movements displace the interface. Interfacial tension acts as a restoring force, leading to interfacial fluctuation and a pressure (sound) save. As the first step, the motion of the interface between a suspension of paramagnetic nanoparticles and a non-magnetized fluid (placed in a cylindrical dish) is measured by phase-sensitive optical coherence tomography (PS-OCT). Experiments were carried out with a range of iron-oxide nanoparticles that were synthesized and surface-coated by our Chemical Engineering collaborators. The numerical method was improved to be volume conserving, and extended to 3D, for more quantitative matching. The measurements of interfacial motion by PS-OCT confirm theoretical predictions of the frequency doubling and importance of material properties, such as the particle size, for the interface displacements. The relative densities of the fluid phase(air/aqueous and dodecane/aqueous) strongly affect the interfacial displacement. Next, the acoustic responses to the external magnetic oscillation, from the rock samples into which different aqueous dispersions of nanoparticles were injected, were measured in terms of the magnetic frequency, nanoparticle concentration, and other process parameters. Subsequently, the PS-OCT displacements in response to the external magnetic oscillation, from the rock samples into which different aqueous dispersions of nanoparticles were injected, were also measured in terms of the magnetic frequency, nanoparticle concentration, and other process parameters. Conclusions and the recommendations for further study are then given. / text

Orientadores: Helio Waldman, Darli Augusto de Arruda Mello / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T09:25:50Z (GMT). No. of bitstreams: 1 Garcia_FranciscoAugustodaCosta_M.pdf: 789247 bytes, checksum: 92fd6bcd2b896f2de173abbf3d6cbef7 (MD5) Previous issue date: 2009 / Resumo: Comparamos o desempenho de quatro arquiteturas de recuperação de portadora tipo feedforward em receptores QPSK e 8-PSK coerentes com multiplexação de polarização e decodificação diferencial. Analisamos os cenários que apresentam desequilíbrio entre as SNRs nas duas polarizações, tal como ocorre em sistemas com PDL. Usando simulações de Monte Carlo, observamos que o método de estimação conjunta proposto apresenta penalidade em SNR de 1,1 dB de penalidade em SNR para uma razão largura de linha/ taxa de símbolo = 5 × 10-3, enquanto as outras três arquiteturas investigadas têm penalidade de 1,8 dB, 2,0 dB, e 3,9 dB para o formato de modulação QPSK. Para o formato 8-PSK, a arquitetura de recuperação conjunta apresenta 1,1 dB para uma razão largura de linha/ taxa de símbolo = 7, 5 × 10-4, enquanto as outras três arquiteturas têm penalidade 1,5 dB, 1,7 dB e 2,8 dB, para BER = 10-3 e um desequilíbrio em SNR de 3 dB. / Abstract: This work compares the performance of four feedforward carrier recovery architectures in coherent QPSK and 8-PSK receivers, with polarization multiplexing and differential decoding. We focused on the scenarios showing an SNR imbalance between orthogonal polarizations, as in PDL impaired systems. Using Monte Carlo simulations, we observed that the proposed joint estimation method yields an SNR penalty of 1.1 dB, for a laser linewidth/ baudrate ratio of 5×10-3, while the other three investigated architectures 1.8 dB, 2.0 dB and 3.9 dB, for the QPSK modulation format. As for 8-PSK, the proposed joint feedforward carrier recovery architecture exhibits a 1.1 dB SNR penalty for a laser linewidth/ baudrate ratio of 7.5 × 10-4, while the other three architectures 1.5 dB, 1.7 dB and 2.8 dB, for a BER = 10-3 and 3 dB SNR imbalance. Keywords: optical communication, coherent receiver, phase modulation. / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Em 2010, doenças cardiovasculares (CVD) causaram 33% do total das mortes no Brasil. O acúmulo de placas lipídicas, calcificadas e/ou fibrosas em vasos sanguíneos é chamado aterosclerose e é uma das principais causas da maioria das internações por doenças coronárias. A implantação de stent é um dos métodos mais comuns para o tratamento de pacientes com obstrução nas coronárias, mas este pode desencadear um crescimento de uma nova íntima e causar novamente o estreitamento do vaso, resultando em problemas de irrigação do coração. Alternativas como Tomografia por Coerência Óptica Intravascular (IOCT) oferecem imagens in vivo para detecção e monitoramento da progressão de CVDs. Adicionalmente, métodos computacionais aplicados a imagens IOCT podem fornecer dados objetivos de estruturas como áreas, perímetros, etc., permitindo mais precisão no diagnóstico. Contudo, ainda é pequena a variedade de métodos quantitativos aplicados a IOCT na literatura, em comparação a outras modalidades relacionadas. Neste trabalho é proposto um método para quantificação da neoíntima após a implantação de stent, fornecendo assim informações para possíveis tratamentos. Para isto são utilizadas imagens reais de IOCT de diferentes fontes: humanos, porcos e coelhos, adquiridas em diferentes períodos após a implantação do stent. Primeiro, é segmentada a parede do vaso (Lúmen), por meio da utilização de modulação de intensidade, filtragem, Fuzzy connectedness e binarização por limiar, seguida de um teste de Branch Opening e um conjunto de operações morfológicas. Segundo, o stent é identificado e segmentado, utilizando características extraídas de derivadas gerando imagens auxiliares à imagem de IOCT seguido pelo emprego de operações de seleção dos possíveis pontos pertencentes ao Stent. Tendo o lúmen e o stent segmentados, a área correspondente à neointima pode ser calculada, executando esse procedimento em imagens do mesmo local adquiridas em períodos diferentes. Assim pode ser feita a quantificação do crescimento de tecido. Para a avaliação do método, é comparada a área segmentada do lúmen e do stent, com os métodos propostos, com a área segmentada manualmente por especialistas (Gold Standard). / In 2010, cardiovascular disease (CVD) caused 33% of the total deaths in Brazil. The accumulation of lipidic, calcified and fibrous plaque, in the vessel wall is called atherosclerosis, and it is the main reason of most admissions in hospitals due to coronary heart disease. The stent implantation is one of the most common methods for coronary obstruction treatment, but this can trigger a neo-intima restenosis, and cause again narrowing of the vessel wall, resulting again in heart-irrigation problems. Modalities such as Intravascular Optical Coherent Tomography (IOCT) can be important for this kind of investigations, because it provides coronary in vivo for detecting and monitoring the progression of CVDs. Additionally, computational methods applied to IOCT images, can render objective structure information, such as areas, perimeters, etc., allowing for more accurate diagnosis. However, the variety of methods in the literature applied in IOCT is still small compared to other related modalities. Therefore, we propose a method for neointima restenosis quantification after stent implantation, thereby providing information to potential treatments. Consequently, we used real IOCT images from different sources: humans, pigs, and rabbits, acquired in different periods after stent implantation. First, the lumen is segmented by using intensity modulation and filtering, next fuzzy connectedness and thresholding is carried out, followed by a \"Branch Opening\" test and a set of morphological operations. Second, the stent is identified and segmented using extracted features by derivative operations, generating auxiliary images to the IOCT. Finally, a set of operations to identify and to select possible points which belong to Stent is performed. Having the lumen and stent segmented the area corresponding to the neo-intima can be calculated. By performing the same procedure in images acquired from the same location at different times, the ratio of the neointima growing can be computed. The evaluation is carried out by comparing the segmented new intima area between the proposed and manual method executed by specialist (Gold Standard).

Em 2010, doenças cardiovasculares (CVD) causaram 33% do total das mortes no Brasil. O acúmulo de placas lipídicas, calcificadas e/ou fibrosas em vasos sanguíneos é chamado aterosclerose e é uma das principais causas da maioria das internações por doenças coronárias. A implantação de stent é um dos métodos mais comuns para o tratamento de pacientes com obstrução nas coronárias, mas este pode desencadear um crescimento de uma nova íntima e causar novamente o estreitamento do vaso, resultando em problemas de irrigação do coração. Alternativas como Tomografia por Coerência Óptica Intravascular (IOCT) oferecem imagens in vivo para detecção e monitoramento da progressão de CVDs. Adicionalmente, métodos computacionais aplicados a imagens IOCT podem fornecer dados objetivos de estruturas como áreas, perímetros, etc., permitindo mais precisão no diagnóstico. Contudo, ainda é pequena a variedade de métodos quantitativos aplicados a IOCT na literatura, em comparação a outras modalidades relacionadas. Neste trabalho é proposto um método para quantificação da neoíntima após a implantação de stent, fornecendo assim informações para possíveis tratamentos. Para isto são utilizadas imagens reais de IOCT de diferentes fontes: humanos, porcos e coelhos, adquiridas em diferentes períodos após a implantação do stent. Primeiro, é segmentada a parede do vaso (Lúmen), por meio da utilização de modulação de intensidade, filtragem, Fuzzy connectedness e binarização por limiar, seguida de um teste de Branch Opening e um conjunto de operações morfológicas. Segundo, o stent é identificado e segmentado, utilizando características extraídas de derivadas gerando imagens auxiliares à imagem de IOCT seguido pelo emprego de operações de seleção dos possíveis pontos pertencentes ao Stent. Tendo o lúmen e o stent segmentados, a área correspondente à neointima pode ser calculada, executando esse procedimento em imagens do mesmo local adquiridas em períodos diferentes. Assim pode ser feita a quantificação do crescimento de tecido. Para a avaliação do método, é comparada a área segmentada do lúmen e do stent, com os métodos propostos, com a área segmentada manualmente por especialistas (Gold Standard). / In 2010, cardiovascular disease (CVD) caused 33% of the total deaths in Brazil. The accumulation of lipidic, calcified and fibrous plaque, in the vessel wall is called atherosclerosis, and it is the main reason of most admissions in hospitals due to coronary heart disease. The stent implantation is one of the most common methods for coronary obstruction treatment, but this can trigger a neo-intima restenosis, and cause again narrowing of the vessel wall, resulting again in heart-irrigation problems. Modalities such as Intravascular Optical Coherent Tomography (IOCT) can be important for this kind of investigations, because it provides coronary in vivo for detecting and monitoring the progression of CVDs. Additionally, computational methods applied to IOCT images, can render objective structure information, such as areas, perimeters, etc., allowing for more accurate diagnosis. However, the variety of methods in the literature applied in IOCT is still small compared to other related modalities. Therefore, we propose a method for neointima restenosis quantification after stent implantation, thereby providing information to potential treatments. Consequently, we used real IOCT images from different sources: humans, pigs, and rabbits, acquired in different periods after stent implantation. First, the lumen is segmented by using intensity modulation and filtering, next fuzzy connectedness and thresholding is carried out, followed by a \"Branch Opening\" test and a set of morphological operations. Second, the stent is identified and segmented using extracted features by derivative operations, generating auxiliary images to the IOCT. Finally, a set of operations to identify and to select possible points which belong to Stent is performed. Having the lumen and stent segmented the area corresponding to the neo-intima can be calculated. By performing the same procedure in images acquired from the same location at different times, the ratio of the neointima growing can be computed. The evaluation is carried out by comparing the segmented new intima area between the proposed and manual method executed by specialist (Gold Standard).

This dissertation is aimed at examining signal integrity degradation factors and realizing signal integrity enhancement circuits for both wired and wireless communication systems. For wired communication systems, an optical coherent system employing an electrical equalization circuit is studied as a way of extending the transmission distance limited by optical fiber dispersion mechanisms. System simulation of the optical coherent receiver combined with the feed-forward equalizers is performed to determine the design specification of the equalizer circuit. The equalization circuit is designed and implemented in a 0.18 µm complementary metal-oxide semiconductor (CMOS) process and demonstrates the capability to extend the transmission reach of long-haul optical systems over single-mode fiber to 600 km. Additionally, for wireless applications, signal integrity issues found in a full-duplex wireless communication network are examined. Full-duplex wireless systems are subject to interference from their own transmitter leakage signals; thus, a transmitter leakage cancellation circuit is designed and implemented in a 0.18 µm CMOS technology. The proposed cancellation circuit is integrated with a low-noise amplifier and demonstrates over 20 dB of transmitter leakage signal suppression.

The scope of this dissertation is to investigate the merits and implications of using multilevel modulation formats in optical communications systems. Following the trend in academia and industry, special focus is placed on quadrature phase-shift keying (QPSK), and specifically on polarization division multiplexed (PDM) QPSK. A special kind of receiver is investigated thoroughly, the digital coherent receiver, the equivalent of the coherent quadrature demodulator in classical communications nomenclature. A large number of digital signal processing (DSP) algorithms are implemented, some of them novel, and their performance is examined, analyzed, and compared in a number of practical system scenarios. The impact of transmitter / receiver imperfections and a number of optical fiber impairments on system performance is studied. Experimental results taken from proof-of-concept experiments are also analyzed. / Η διατριβή αυτή έχει ως σκοπό τη μελέτη οπτικών τηλεπικοινωνιακών συστημάτων που χρησιμοποιούν τετραδικές διαμορφώσεις φάσης, πολυπλεξία κατά πόλωση και σύμφωνους ψηφιακούς δέκτες διαφοροποίησης φάσης και πόλωσης. Μελετήθηκαν αλγόριθμοι επεξεργασίας σήματος κατάλληλοι για εξάλειψη της επίδρασης των φαινομένων διάδοσης και των μη ιδανικοτήτων οπτικών τηλεπικοινωνιακών συστημάτων. Η μελέτη έγινε με προσομοίωση Monte-Carlo, με χρήση ημιαναλυτικής μεθόδου προσδιορισμού της πιθανότητας σφάλματος τηλεπικοινωνιακού συστήματος και με ανάλυση πειραματικών δεδομένων. Τα πειραματικά δεδομένα ελήφθησαν από οπτικό τηλεπικοινωνιακό σύστημα με τετραδική διαμόρφωση φάσης και πολυπλεξία κατά πόλωση με ρυθμούς συμβόλων 0.1-10 GBd (0.4-40 Gb/s). Μελετήθηκαν αλγόριθμοι επανένωσης των πολώσεων, αλγόριθμοι αποπολύπλεξης των πολώσεων, αλγόριθμοι διόρθωσης της ανισοσταθμίας ορθογωνιότητας, αλγόριθμοι εκτίμησης και αφαίρεσης της ενδιάμεσης συχνότητας και αλγόριθμοι εκτίμησης και αφαίρεσης του θορύβου φάσης των laser.